The mother of a New York University student recovering in the hospital after being trapped between two buildings says her son "can't remember" how he got stuck and that he has several broken bones and possibly a fractured pelvis.

"He really can't remember up until when he fell in there, exactly what happened. Maybe as he comes to," mom Habiba Vongtau told ABC's New York station WABC. "[He has] broken bones, arm, and contusions, and I think [a] fractured pelvis."

Firefighters arrive shortly after 5 p.m. on Sunday and had to break through a concrete wall to get to Asher Vongtau, 19, who was wedged in a coffin-sized space between a 17-story NYU dormitory and a parking garage in lower Manhattan.

"We had an unconscious male stuck in between two buildings," an FDNY spokesman told ABCNews.com. "We had to breach a wall to gain access to get him out. We had him in serious condition and he was rushed to Bellevue Hospital."

A firefighter on-scene told WABC that Vongtau's legs were crossed, he was on his side and he was moving his right arm.

Vongtau was stuck at the ground floor, the FDNY said. The rescue took about an hour-and-a-half. It is unclear how he got wedged in between the two buildings. Officials believe he may have been trapped for up to two days, according to ABC's New York station WABC.

Friends told WABC that they reported him missing after a fire alarm drill. When they called authorities to file a missing persons report, they were also told to check the roof of the building.

"We went door-to-door asking people what they knew about him and one person told us that the last that they'd seen, he was headed up the stairs," Vongtau's friend Michael Yablon told WABC.

Yablon said the friends went to security and told them they needed to check the roof. He said Vongtau's cell phone was found on the roof and that led to finding him.

"Had we not told the security guards -- the three of us 19-year-old students -- to check the roof, they would not have found him for who knows how long and he would probably be dead right now," a distressed Yablon said.

NYU said their Department of Public safety first received word of a missing student at about 12:30 a.m. on Sunday morning and "immediately began a search" that included NYU locations, local precincts and area emergency rooms. Vongtau's possessions were found later on Sunday at the residence hall.

"One of our Public Safety sergeants in the course of his search of the building extended his search to a narrow space between our building and an abutting garage, where he discovered someone wedged into the space and heard moaning," NYU spokesman John Beckman said in a statement.

"The FDNY and the NYPD were immediately called; they responded and rescued the student. Our understanding is that the student was conscious and able to communicate with rescuers throughout the rescue," Beckman said. "The circumstances of how the student came to be in this space remain unclear to us."

Vongtau is in fair condition at Bellevue Hospital, according to the hospital.